Meshing fails for a spherical structure with little particles on the surface

Meshing fails for a spherical structure with little particles on the surface

I have been trying to mesh the structure I attached here. This structure has two concentric spheres with radii of 30 and 26. These are encapsulated by two layers of smaller particles that are randomly distributed on the surface. Each little particle layer has a little gap around 0.2. This whole structure fails to mesh with NETGEN 1D-2D-3D. This mesh option throws an errors stating "NgException at Surface meshing: Problem in Surface mesh generation" for all FACES that are failed to mesh.

I also tried applying limit tolerance and meshing each component separately with NETGEN 1D-2D-3D. This option helps meshing the first layer of little-particle-shell but does not work the outer surface.

Another thing I have tried is using "Tetrahedron(Netgen)" with the assignment of hypothesis, 3D:Automatic Tetrahedralization, and Tetrahedrpn (HYBRID). These options would stop SALOME working and shutting itself down with an error window stating "SALOME_Session_Server.exe has stopped working".